What are NAND, NOR, and XNOR Gates ?
NAND, NOR, and XNOR gates are variations of the basic logic gates (AND, OR, and XOR) combined with an inverter. Each of these gates has distinct characteristics:
- NAND Gate: The NAND (NOT AND) gate is the inverse of an AND gate. It outputs false (0) only when all its inputs are true (1).
- NOR Gate: The NOR (NOT OR) gate is the inverse of an OR gate. It outputs true (1) only when all its inputs are false (0).
- XNOR Gate: The XNOR (Not eXclusive OR) gate is the inverse of an XOR gate. It outputs true (1) when its inputs are equal (both true or both false).
The truth tables for these gates are derived by inverting the output of their respective basic gates. The little circle after the symbol represent the inverter.
| Input A | Input B | Output |
|---|---|---|
| 0 | 0 | 1 |
| 0 | 1 | 1 |
| 1 | 0 | 1 |
| 1 | 1 | 0 |
| Input A | Input B | Output |
|---|---|---|
| 0 | 0 | 1 |
| 0 | 1 | 0 |
| 1 | 0 | 0 |
| 1 | 1 | 0 |
| Input A | Input B | Output |
|---|---|---|
| 0 | 0 | 1 |
| 0 | 1 | 0 |
| 1 | 0 | 0 |
| 1 | 1 | 1 |